I disagree with Bob that 2) makes no sense. I read its meaning as follows:

- I saw Joan.
- I also saw other women. These (in contrast to Joan) I found interesting.

The comma between 'other' and 'interesting' in 2) marks them off from each other, making them separate and distinct descriptors. This separateness also serves to contrast the interesting quality of these women with the implied boringness of Joan. (In speech, you would insert a noticeable pause here and give extra emphasis to the word 'interesting'.)

I was tempted to agree with Bob on the basis that a "what" was needed to complete "Joan and other what" .

But a few more thoughts, in this more liberal world we must inhabit, led me to : "Joan and partner", "Joan plus one". Then "Joan and other" became a homosexual couple.

In this scenario one might imagine that the speaker was suggesting that both Joan and her female partner were both interesting people. And to a more reserved speaker the "interesting couple" may be arched such that it was the mere coupling of the two females that was the interesting part.